21264930 has 56 divisors (see below), whose sum is σ = 57408732. Its totient is φ = 5668704.

The previous prime is 21264923. The next prime is 21264931. The reversal of 21264930 is 3946212.

21264930 is a `hidden beast` number, since 2 + 12 + 649 + 3 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19368801 + 1896129 = 4401^2 + 1377^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21264894 and 21264903.

It is not an unprimeable number, because it can be changed into a prime (21264931) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 5832 + ... + 8748.

Almost surely, 2^21264930 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21264930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28704366).

21264930 is an abundant number, since it is smaller than the sum of its proper divisors (36143802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21264930 is an equidigital number, since it uses as much as digits as its factorization.

21264930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2942 (or 2927 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21264930 is about 4611.3913301736. The cubic root of 21264930 is about 277.0477659637.

It can be divided in two parts, 2126 and 4930, that added together give a square (7056 = 84²).

The spelling of 21264930 in words is "twenty-one million, two hundred sixty-four thousand, nine hundred thirty".